<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			function array_max()
			{
				var max=this[0]
				for(var i=0;i<this.length;i++)
				{
					if(max<this[i])
					{
						max=this[i]
					}
				}
				return max
			}
			Array.prototype.max=array_max
			
			var nums=new Array(1,2,4,64,13)
			
			document.write(nums.max())
			
			
		</script>
	</body>
</html>
